Heat transfer usually involves energy exchange between two domains of different physical properties (e.g., a solid region and a fluid region, two different solid regions, or two different fluid regions). Heat transfer simulations are very important in many engineering applications. For example, automotive under-hood heat transfer problems often involve conjugate heat transfer analyses between solid and fluid regions. Specifically, the conductive heat transfer in a solid region is often coupled to the convective heat transfer in a neighboring fluid flow. Usually, an interface is created between the solid region and the fluid region to enable modeling transfer of energy, mass, and/or momentum.
The finite-volume method (FVM) is a numerical analysis technique which can be used to represent and evaluate partial differential equations in the form of algebraic equations. Similar to finite element analysis, values are calculated at discrete places on a meshed geometry. A mesh corresponds to a discretization of the geometrical domain and includes a collection of mesh elements. The mesh elements often have simple shapes. For example, zero-dimensional mesh elements include vertices, one-dimensional mesh elements include lines, two-dimensional mesh elements include triangles or quandrangles, and three-dimensional mesh elements include tetrahedra, hexahedra or prisms.
“Finite volume” refers to a small volume surrounding each node point on a mesh. In the finite volume method, volume integrals in a partial differential equation that contains a divergence term are converted to surface integrals, using a divergence theorem. These terms are then evaluated as fluxes at the surfaces of each finite volume.